Refrigerator with internal compartment divisible into independent temperature zones

ABSTRACT

A refrigerator comprises a refrigerator housing having a compartment, this latter presenting side walls having brackets for at least one removable element for supporting products to be preserved and separating the compartment into separate zones, the compartment having a rear wall in correspondence with which an evaporator is present, in the rear wall there being provided a plurality of apertures disposed in overlying planes and communicating with the evaporator, an electronic circuit being provided for measuring the internal temperature of the compartment. The evaporator is located in correspondence with rear wall apertures of the compartment, on these latter there being disposed motor-driven fans, the fans being mutually independent to enable different independent temperatures to be created within the different compartment zones.

The present invention relates to a refrigerator in accordance with theintroduction to the main claim. Herein, the term “refrigerator” meanseither an upright refrigerator in which the temperature is normallygreater than −2° C., or a freezer in which the temperature is maintainedconstantly below 0° C.

As is well known, in a refrigerator (static or forced-air) it is veryimportant to achieve a correct temperature in each of its preservationor freezing compartments in order to obtain optimum preservation of thefoods stored in it. In particular, it is well known that different foodsstorable in the compartment for preservation require differentpreservation temperatures, as for example the case of meat and fishcompared with vegetables or dairy products.

It is known to form within a refrigeration compartment a plurality ofpreservation zones at different temperatures, for example by creatingactual preservation zones provided with a separate perimetral structureand an independent access door. These zones can be positioned inside therefrigeration compartment.

The aforesaid solution involves high construction costs and can also becomplicated to use.

Also known, for example from EPO 805320 which forms a pre-characterisingpart of the main claim of the present document, is a forced-airrefrigerator having a preservation compartment divided into severalpreservation zones by usual removable elements or shelves arranged tosupport the products to be preserved. Air can be drawn into each ofthese zones from an evaporator positioned within a predefined containingcavity created within the refrigeration cell behind the rear wall of thepreservation compartment in which the usual forced air circulation fanis also located ; the air penetrates into the various zones of therefrigeration compartment through apertures formed in the rear wall ofthis compartment at different heights in parallel planes. The quantityof air which penetrates into the various zones is set and controlled bya rotary blade provided on a rod supporting a plurality of deflectors:this blade is positioned vertically behind the rear wall of therefrigeration compartment below the evaporator such that the deflectorslie in correspondence with the apertures provided in the rear wall ofthe refrigeration compartment.

By moving the rotary blade about its axis the air can be distributed ina balanced manner within the various zones of the refrigerationcompartment, for example such as to feed cold air intensely into a partof the high temperature compartment.

This solution is applicable only in a forced-air refrigerator, it is ofcomplicated and costly construction, it does not enable air to circulatewithin a single zone of the refrigeration compartment to achieve thereina temperature totally independent of that of the other zones of therefrigeration compartment, and can give rose to reliability andmaintenance problems.

Finally, from a preceding patent application of the same Applicant arefrigerator is known, in the compartment of which there is positionedat least one removable element for supporting foods, for example ashelf, box or the like, comprising an element to be positioned onsupports present on opposing walls of the refrigeration compartment.

Associated with said element there are provided setting means enablingthe internal temperature of the refrigeration compartment to be set andthe set temperature value to be transferred to means for controlling therefrigeration circuit of the refrigerator.

The said solution enables excellent control of the internal temperatureof a refrigeration compartment to be achieved.

However the aforesaid patent application did not have as an object theobtaining of zones at different mutually independent temperatures withinthe refrigeration compartment.

An object of the present invention is to provide a refrigerator, withinthe compartment of which zones at mutually independent temperatures canbe obtained.

Another object is to provide a refrigerator of the stated type which isof simple and reliable construction.

A further object is to provide a refrigerator of the stated type whichenables localized control of the temperature of each zone into which therefrigeration compartment is divided.

Another object is to provide a refrigerator of the stated type which issimple and immediate to use.

These and further objects which will be apparent to the expert of theare attained by a refrigerator in accordance with the accompanyingclaims.

The present invention swill be more apparent from the accompanyingdrawing, which is provided by way of non-limiting example and in which:

FIG. 1 is an exploded partial front perspective view of a refrigeratoraccording to the invention;

FIG. 2 is a front perspective view of the refrigerator of FIG. 1; and

FIG. 3 is a schematic front perspective view of a shelf used in therefrigerator of FIG. 1 but forming the subject of a preceding filing ofthe same Applicant.

Said figures schematically show a refrigerator indicated overall by 1.In the example, the refrigerator is an upright refrigerator andcomprises a housing 1A bounding an internal compartment 2 havingopposing side walls 3, 4 and a rear wall or shoulder 5. Usual supports 6are present on the lateral walls, to support shelves 7K, 7W, 7X formedin accordance with a patent application already filed in the name of thesame Applicant.

Each shelf 7K, 7W, 7X comprises (see FIG. 3) means 10 to enable theinternal temperature of the compartment 2 (or a temperature rangecorresponding to a determined food category) to be set and possibly tobe measured. These means 10 cooperate with control means 11 forcontrolling the operation of the refrigerator 1, by controlling andregulating, on the basis of the temperature setting imposed by thesetting means 10, the operation of a usual refrigeration circuitschematically shown in FIG. 3 and indicated by 12.

The setting means 10 are associated with operating means 13 positionedpreferably on a front face 14 of the body 15 of the shelf 7. These meansfor setting the internal temperature of the compartment 2 are anelectrical and/or electronic circuit 16 suitably inserted into the body15, for example an electrical circuit of passive type defined by an RLCresonant circuit and comprising an inductor 17 positioned incorrespondence with a lateral face 18 of the body 15 of the shelf 7K, 7Wor 7X and a plurality of capacitors (for example three, as in thefigures where they are indicated by 20, 21 and 23) of variouscapacitances. Each capacitor is connected on one side to an electricalline 26 connected to one end of the inductor 17, and on the other sideto a change-over switch (28, 30 and 32 respectively) arranged to connecteach capacitor to a second electrical line 35, 36 and 37 respectively,connected to an electrical branch 38 connected to the other end of theinductor 17.

Using the operating means 13, a different change-over switch can beactivated to connect the corresponding capacitor to the inductor in sucha manner as to modify the resonance frequency of the circuit 16.

The operating means 13 can be defined by a plurality of pushbuttonsconnected to the various capacitors and which, when pressed, result inthe selection of a temperature suitable for preserving different foods.Alternatively, the operating means 13 can be defined by a slidableselector 39 movable along the face 14 of the body 15 of the shelf 7.Hence a respective desired temperature within the compartment 2 can bemade to correspond to each frequency variation of the circuit 16, thistemperature being selected for example via the selector 39.

An inductor 41 is positioned in that wall 4 of the compartment 2 whichfaces the face 18 of the body 15 of the shelf 7K, 7W or 7X, and isconnected to an oscillating circuit 42 connected to the refrigeratorcontrol means 11, for example a microprocessor circuit.

On powering the oscillating circuit 42, the circuit 16 is activated, sothat each variation in the resonance frequency of said circuit is notedas a variation in the resonance of the circuit 42, this being thendetermined by the control circuit or means 11.

Moreover, any deviation in the actual temperature from that set for eachshelf 7K, 7W, 7X can be determined directly by the circuit 11, as thistemperature variation results in a proportional variation in thecapacitance of the capacitor selected by the circuit 16 and hence avariation in the resonance frequency of said circuit (determined by thecontrol circuit 11). This circuit acts on the refrigeration circuit 12on the basis of this determination. Alternatively each zone of the cellcan be provided with temperature sensors, positioned for example incorrespondence with the side wall.

Each shelf 7K, 7W, 7X comprises a perimetral frame 7A (where theoperating means 13 are positioned), a central part 7B (containing themeans 10) and a frame insert 7C to be positioned to the front of therear wall or shoulder 5 of the compartment 2. This rear wall is definedby a panel 60 presenting a projecting central portion 61 disposed in asubstantially central position on the wall 5. In the portion 61 thereare provided a plurality of through apertures 63 where frames 64 arepositioned for supporting motor-driven fans 65 operated and controlledin their operation by the control circuit 11. Said circuit can controlnot only the speed of the fans 65 but also the speed of the compressormotor if a variable-speed compressor is used.

Other through apertures 66 are provided in lateral portions 67 of thepanel 60 to the side of the projecting portion 61, and are covered bygrilles 69.

To the rear of the panel 60, between it and a rear portion 70 of thehousing 1A, an evaporator 71 for the refrigeration circuit is positionedvertically within a cavity 72 (or a conduit positioned centrally on thewall 5 of the compartment 2) of the panel 60 defined by the projectingportion 61. Preferably the evaporator consists of several portions offinned tube connected together ands has a suitable length, for exampleequal to that of the portion 61.

By virtue of the invention, zones can be obtained within the compartment2 which are at different mutually independent temperatures based on thetype of foods placed on the shelf 7K, 7W or 7X. In this manner zones canbe obtained for preserving meat and fish, vegetables and dairy products;said zones are not however predetermined, and can be mutually exchanged.

It will now be assumed that a refrigerator such as that described is tobe used. With reference to FIG. 2, this shows four zones: a first zone Apositioned above the shelf 7K, a second zone B positioned between theintermediate shelf 7W and the upper shelf 7K, a third zone C positionedbetween the shelves 7W and 7X, and a fourth zone D positioned below theshelf 7X (between this latter and a usual lower drawer, not shown). Theapertures 63 with the fans 65 and the apertures 66 are present at eachzone of the refrigeration compartment.

Using the operating means 13 of each shelf 7, a particular requiredtemperature is set for that zone of the compartment 2 above the shelf.On the basis of the aforesaid setting, the control means 11 act on therefrigeration circuit 123 and on the fans 65 which forcibly feed intothe various zones A, B, C, D of the compartment 2 cold air withdrawnfrom the cavity 72 containing the evaporator 71. The cold air is fed inthe required quantity and for the required time to enable thetemperature set by the user to be achieved within the aforesaid zones ofthe compartment 2. At the same time warmer air returns to the cavity 72through the apertures 66.

The temperature is measured by the said circuit 16 of each shelf 7K, 7W,7X which then enables the control means 11, in the manner known from thepreceding patent application in the name of the same Applicant, todetermine this temperature and to adjust the speed of the fans 65 inorder to maintain the temperature achieved. If, via the operating means13, the user sets a change to the temperature in the compartment above ashelf, the means 11 sense this change (in the manner already describedin the aforesaid already filed patent application in the name of thesame Applicant) and act in the described manner on the fans 65 to enablethe required temperature to be achieved within the compartment.

According to a further characteristic of the invention, particularcolours generated in the various zones A, B, C and D of the compartment2 are associated with the various temperatures seftable by the user. Thepreferably diffused coloration in the various zones can be obtained byfluorescent lamps or light emitting diodes (LEDs), or by colouredplastics (or coloured adhesives) positioned in correspondence with(superposed on) white light sources, or another known means. In FIG. 2,the coloured light generating member is indicated overall by 100 and ispositioned on the wall 3 in correspondence with the each zone A, B, C, Dof the compartment 2. As an alternative, the side wall of the cell canbe provided with a light channel arranged to assume a differentcoloration within the portion corresponding to a zone of the cell. Thisdifferent coloration is for example obtainable by using multicolour LEDsof RGB type.

The aforesaid “calorimetric” characteristic enables the consumer tomanage these optimized zones or spaces without difficulty: for example,the optimum zone for preserving meat can be of intense blue colour,whereas that for dairy products can be of a different shade of blue orof another colour, for example white. To prevent difficulty inunderstanding the colour-food concept, food products are associated ingroups for which optimum common preservation conditions have beendefined: hence a different colour will be associated with each category.

This solution facilitates food storage: in this respect, after selectingvia a control panel the type of food to be inserted into the compartment2, the selection is automatically indicated to the user by a display onthe door or by the internal coloration of the cell. As the colour isrelated to a category of foods, this will hence indicate the correctposition where the food is to be placed.

Besides facilitating storage, the colorimetric solution within thecompartment 2 can be useful for two other reasons: once the user isfamiliar with the food-colour mechanism, on the one hand the internalcoloration of the compartment 2 is useful as a general indicator of whatis contained in the refrigerator (for example that meat or vegetablesare lacking because a particular colour is missing), and on the otherhand it can be utilized as an indicator of appliance malfunction; it canfor example also be developed as an alarm indicator for foodpreservation temperature tolerances (by becoming red if the temperatureis excessive because of appliance malfunction).

According to a variant of the invention, the shelves 7K, 7W and 7X arenormal shelves without the means 10 and the means or members associatedwith them. In that case the spaces A, B, C, D are predefined within thecompartment 2 even though with variable volumes (for example they can bedefined by the position of particular groups of supports 6 on which toposition a shelf at variable heights), in these there being positionedtemperature sensors and thermostats associated with a wall 3 or 4 of thecompartment 2 and connected to the control means 11 (present in anyevent). These latter, on noting the temperature setting by the user viathe thermostat, act on the fans 65 to maintain the set temperatureswithin the zones of the compartment 2; temperature control within eachzone is obtained via the sensor or sensors located within them.

Other solutions are possible in the light of the present description andare to be considered as lying within the scope of the present document.

1. A refrigerator comprising a refrigerator housing having acompartment, the compartment presenting side walls having brackets forat least one removable element for supporting products to be preservedand separating the compartment into separate zones, the compartmenthaving a rear wall in correspondence with which an evaporator ispresent, in the rear wall there being provided a plurality of aperturesdisposed in overlying planes and communicating with the evaporator, ameans being provided for measuring the internal temperature of thecompartment, the evaporator is located in correspondence with theapertures provided in the rear wall of the compartment, on the aperturesthere being disposed a means for drawing air from the evaporator to theinternal compartment, the air drawing means being mutually independentto enable different independent temperatures to be created within thedifferent zones of the refrigeration compartment, the temperature ofeach zone being able to be set and modified by a user.
 2. A refrigeratoras claimed in claim 1, wherein the air drawing means are motor-drivenfans.
 3. A refrigerator as claimed in claim 1, wherein the rear wall ofthe compartment comprises a panel located in front of a rear wall of therefrigerator housing, in the panel there being provided the aperturesfor the air drawing means.
 4. A refrigerator as claimed in claim 3,wherein the panel comprises a raised part facing towards therefrigeration compartment, this part being disposed vertically withinthe compartment, between the raised part and the wall of therefrigerator housing there being present a cavity within which theevaporator is positioned, the cavity at least partly containing theevaporator.
 5. A refrigerator as claimed in claim 4, wherein theevaporator lies vertically and comprises at least one finned tube.
 6. Arefrigerator as claimed in claim 1, wherein the rear wall of therefrigeration compartment comprises further recirculation aperturespositioned to the side of the preservation where the air drawing meansare disposed, the recirculation apertures enabling air to berecirculated from the refrigeration compartment to the evaporator.
 7. Arefrigerator as claimed in claim 1, wherein the air drawing means arecontrolled by control means, the control means controlling the operationof the refrigeration circuit of the refrigerator.
 8. A refrigerator asclaimed in claim 1, wherein the various zones of the refrigerationcompartment in which different temperatures can be obtained, there areprovided setting means to enable a desired temperature to be set, andmeasurement means to enable the temperature present to be measured.
 9. Arefrigerator as claimed in claim 8, wherein the setting means and themeasurement means are associated with each shelf.
 10. A refrigerator asclaimed in claim 8, wherein the setting means and the measurement meansare associated with at least one wall of the refrigeration compartment.11. A refrigerator as claimed in claim 1, wherein coloured means areprovided to define the temperature of utilization of each zone of therefrigeration compartment.
 12. A refrigerator as claimed in claim 11,wherein the coloured means are coloured light-emitting means.
 13. Arefrigerator as claimed in claim 11, wherein the coloured means arecoloured bodies, advantageously superposed on a light source.
 14. Arefrigerator as claimed in claim 11, wherein the coloured means areassociated with each shelf.
 15. A refrigerator as claimed in claim 11,wherein the coloured means are associated with at least one wall of therefrigeration compartment.
 16. A refrigerator as claimed in claim 11,wherein the coloured means change colour on the basis of the temperaturepresent in each zone of the refrigeration compartment.